What is first-class environments?

Being first-class means environments are in the domain of values in the language.

think first class functions

We need two rules:

• create this value (introduction)
• use it (elimination)

by providing ways to

• save a snapshot of current environment
• execute code in a specific environment

(let ((my-env (let ((x 42)
                (capture-environment)))))
(let ((x 23))
  (with-environment x my-env)))

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